Strosser U.S. Pat. No. 4,624,180 discloses a microprocessor-based control circuit for controlling a large rectangular baler by sensing the load placed on load cells as a plunger compresses crop material into bales in the bale case of the baler. The load cells are strain gages such as piezoelectric or resistive devices which sense shear stresses as the plunger compacts crop material and forces it through the bale case. The output signals from the load cells may be analyzed by a microprocessor-based control circuit to develop control signals for adjusting tension rails comprising part of the bale case. By adjusting the tension rail pressure, the density of crop material in formed bales may be controlled. The load cells, particularly if they are piezoelectric devices, are subject to both mechanical failure (separation of strain gage from structural member whose stress it is measuring) and electrical failure (broken leads or loose connections). When a load cell fails on such a baler the unit must be operated manually. This is inconvenient, causes down-time, and results in lower density bales. On the other hand, the operator may wish to continue the baling operation because of impending adverse weather conditions or for other reasons. The present invention provides a temporary solution to this problem, permitting the baler to remain in operation until it is more convenient to return it to a shop for repairs.